Osmium oxide fluorides

The possibility that a third osmium(VII) oxide fluoride exists remains, since a dimorphic crystalline material of unknown composition, but thought to be either 0s02F2 or Os03F, was produced during the reaction of OsF6 with Pyrex glass (185). 

Figure 2 — Molecular structure of osmium oxide penta-fluoride OsOFg ...

In order to better understand the factors which are involved in limiting the oxidation state of osmium, a search for high valent oxyfluorides was undertaken. In particular, since six-co-ordinate osmium occurs in the readily formed hexafluoride, both osmium dioxide tetra-fluoride and osmium oxide pentafluoride appeared possible. 

Manganese trichloride oxide, 4141 Manganese trifluoride, 4335 Mercury(II) bromide, 0269 Mercury(I) fluoride, 4312 Mercury(II) iodide, 4602 Molybdenum hexafluoride, 4365 Molybdenum pentachloride, 4180 Neptunium hexafluoride, 4366 Osmium hexafluoride, 4370 Palladium tetrafluoride, 4347 Palladium trifluoride, 4341... 

Nitrosyl tetrafluorochlorate, 3985 Nitrous acid, 4435 Nitryl chloride, 4025 Nitryl fluoride, 4303 Nitryl hypochlorite, 4026 Nitryl hypofluorite, 4304 Nitryl perchlorate, 4029 Osmium hexafluoride, 4370 Osmium(VIII) oxide, 4858 Oxygen (Gas), 4831 Oxygen (Liquid), 4832 Oxygen difluoride, 4317 Ozone, 4846... 

Chloroxytrifluoromethane, 26 137-139 reactions, 26 140-143 addition to alkenes, 26 145-146 oxidative addition, 26 141-145 vibrational spectra, 26 139 Chloryl cation, 18 356-359 internal force constants of, 18 359 molecular structure of, 18 358, 359 properties of, 18 357, 358 synthesis of, 18 357, 358 vibrational spectra of, 18 358, 359 Chloryl compounds, reactions of, 5 61 Chloryl fluoride, 18 347-356 chemical properties of, 18 353-356 fluoride complexes of, 5 59 molecular structure of, 18 349-352 physical properties of, 18 352, 353 preparation, 5 55-57 and reactions, 27 176 properties of, 5 48 reactions, 5 58-61, 18 356 synthesis of, 18 347-349 thermal decomposition of, 18 354, 355 vapor pressures, 5 57, 18 353 vibrational spectra of, 18 349-352 Chloryl ion, 9 277 Cholegobin, 46 529 Cholesterol, astatination, 31 7 Cholorofluorphosphine, 13 378-380 h CHjPRj complexes, osmium, 37 274 Chromatium, HiPIP sequence, 38 249 Chromatium vinosum HiPIP, 38 108, 133 Fe4S4 + core, 33 60 Chromato complexes, osmium, 37 287... 

Nitrogen dioxide, 4720 Nitrogen oxide, 4719 Nitrosyl chloride, 4017 Nitrosyl fluoride, 4296 Nitrosyl perchlorate, 4021 Nitrosyl tetrafluorochlorate, 3979 Nitrosylsulfuric acid, 4432 Nitrous acid, 4429 Nitryl chloride, 4019 Nitryl fluoride, 4297 Nitryl hypochlorite, 4020 Nitryl hypofluorite, 4298 Nitryl perchlorate, 4023 Osmium hexafluoride, 4364 Osmium(VIII) oxide, 4852 Oxygen difluoride, 4311 Oxygen (Gas), 4825 Oxygen (Liquid), 4826 Ozone, 4840... 

It has been suggested (79) that polymorphism may occur for transition metal pentafluorides as it does for oxide tetrafluorides (91). X-Ray powder photographs of products from the reduction of hexafluorides in anhydrous hydrogen fluoride (79) showed that the samples of rhenium and osmium pentafluorides had different structures from those previously reported, but no unit-cell dimensions could be derived. 

Phillips and Timms [599] described a less general method. They converted germanium and silicon in alloys into hydrides and further into chlorides by contact with gold trichloride. They performed GC on a column packed with 13% of silicone 702 on Celite with the use of a gas-density balance for detection. Juvet and Fischer [600] developed a special reactor coupled directly to the chromatographic column, in which they fluorinated metals in alloys, carbides, oxides, sulphides and salts. In these samples, they determined quantitatively uranium, sulphur, selenium, technetium, tungsten, molybdenum, rhenium, silicon, boron, osmium, vanadium, iridium and platinum as fluorides. They performed the analysis on a PTFE column packed with 15% of Kel-F oil No. 10 on Chromosorb T. Prior to analysis the column was conditioned with fluorine and chlorine trifluoride in order to remove moisture and reactive organic compounds. The thermal conductivity detector was equipped with nickel-coated filaments resistant to corrosion with metal fluorides. Fig. 5.34 illustrates the analysis of tungsten, rhenium and osmium fluorides by this method. 

Oxidation states IV to VIII inclusive are represented in the fluorine chemistry of osmium, as compared with III to VI for ruthenium and II and III for iron. Thus the fluorides of the iron-ruthenium-osmium triad well exemplify the greater tendency of second and third row elements to higher oxidation states with rc-donor ligands. 

The NO + MF, (except NO -f WF,) reactions proceed spontaneously at 20°. The reactions were followed tensimetrically. Gaseous products were identified by infrared spectroscopy and the solid products were examined by. y-ray powder-photography. Both ReF, and OsF, formed NO+[MF,] (cub.) salts and neither salt could be induced to combine with more NO to yield the quadrivalent (NO),MF, compound. In their reactions with nitrosyl fluoride at 20°, however, the rhenium and osmium fluorides are clearly differentiated ReF, readily forms a thermally stable 2 1 adduct, which is isomorphous with (NOjjWFg, whereas the OsF, -i- ONF reaction is complex. The identification of small quantities of nitrogen oxide trifluoride, in the gaseous product of the reaction, indicate the existence of an... 

---